drm/radeon/kms: more r4xx lvds fixes

Grab pll ref div from regs at driver init.  r4xx seems very
picky about the dividers for the pll driving lvds.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
3 files changed